I second the dwarf crenicichla - belonesox are kind of boring on their own, they just kinda float and wait for food. They're better suited to a community setting of deep-bodied, peaceful fish (they do well with angels/discus/the larger barbs, etc.). The dwarf crenicichla are just like their larger counterparts, always on the move, investigating things, etc, plus IMO they're just that much more attractive than belonesox. Belonesox are great fish, don't get me wrong, just not the kind of fish I'd dedicate a tank to.
